WHMCS WP Integration Installation Error

I get the following errors on installation and activation.

Warning: chmod(): Operation not permitted in /home/content/p3pnexwpnas03_data03/36/2360136/html/wp-content/plugins/whmcs-wordpress-integration/whmcs-integration.php on line 575

Warning: chmod(): Operation not permitted in /home/content/p3pnexwpnas03_data03/36/2360136/html/wp-content/plugins/whmcs-wordpress-integration/whmcs-integration.php on line 575

WHMCS Integration cannot patch file wp-includes/class-http.php. Make sure it is writable